Add tests for Docker & Legacy Docker buildpacks

tests/test_cache_from.py

@@ -4,21 +4,79 @@ Test that --cache-from is passed in to docker API properly.
 import os
 import docker
 from unittest.mock import MagicMock, patch
+from repo2docker.buildpacks import BaseImage, DockerBuildPack, LegacyBinderDockerBuildPack
 from tempfile import TemporaryDirectory
 
-def test_cache_from(monkeypatch):
+def test_cache_from_base(monkeypatch):
     FakeDockerClient = MagicMock()
     cache_from = [
         'image-1:latest'
     ]
+    fake_log_value = {'stream': 'fake'}
     fake_client = MagicMock(spec=docker.APIClient)
-    fake_client.build.return_value = iter([{'stream': 'fake'}])
+    fake_client.build.return_value = iter([fake_log_value])
 
     with TemporaryDirectory() as d:
+        # Test base image build pack
         monkeypatch.chdir(d)
-        from repo2docker.buildpacks import BaseImage
         for line in BaseImage().build(fake_client, 'image-2', '1Gi', {}, cache_from):
-            assert line == {'stream': 'fake'}
+            assert line == fake_log_value
         called_args, called_kwargs = fake_client.build.call_args
         assert 'cache_from' in called_kwargs
-        assert called_kwargs['cache_from'] == cache_from
+        assert called_kwargs['cache_from'] == cache_from
+
+
+
+def test_cache_from_docker(monkeypatch):
+    FakeDockerClient = MagicMock()
+    cache_from = [
+        'image-1:latest'
+    ]
+    fake_log_value = {'stream': 'fake'}
+    fake_client = MagicMock(spec=docker.APIClient)
+    fake_client.build.return_value = iter([fake_log_value])
+
+    with TemporaryDirectory() as d:
+        # Test docker image
+        with open(os.path.join(d, 'Dockerfile'), 'w') as f:
+            f.write('FROM scratch\n')
+
+        for line in DockerBuildPack().build(fake_client, 'image-2', '1Gi', {}, cache_from):
+            assert line == fake_log_value
+        called_args, called_kwargs = fake_client.build.call_args
+        assert 'cache_from' in called_kwargs
+        assert called_kwargs['cache_from'] == cache_from
+
+        # Test legacy docker image
+        with open(os.path.join(d, 'Dockerfile'), 'w') as f:
+            f.write('FROM andrewosh/binder-base\n')
+
+        for line in LegacyBinderDockerBuildPack().build(fake_client, 'image-2', '1Gi', {}, cache_from):
+            print(line)
+            assert line == fake_log_value
+        called_args, called_kwargs = fake_client.build.call_args
+        assert 'cache_from' in called_kwargs
+        assert called_kwargs['cache_from'] == cache_from
+
+
+def test_cache_from_legacy(monkeypatch):
+    FakeDockerClient = MagicMock()
+    cache_from = [
+        'image-1:latest'
+    ]
+    fake_log_value = {'stream': 'fake'}
+    fake_client = MagicMock(spec=docker.APIClient)
+    fake_client.build.return_value = iter([fake_log_value])
+
+    with TemporaryDirectory() as d:
+        # Test legacy docker image
+        with open(os.path.join(d, 'Dockerfile'), 'w') as f:
+            f.write('FROM andrewosh/binder-base\n')
+
+        for line in LegacyBinderDockerBuildPack().build(fake_client, 'image-2', '1Gi', {}, cache_from):
+            assert line == fake_log_value
+        called_args, called_kwargs = fake_client.build.call_args
+        assert 'cache_from' in called_kwargs
+        assert called_kwargs['cache_from'] == cache_from
+
+